The World Health Organization on Friday declared a new coronavirus variant, named Omicron, to be "of concern" after it was detected in South Africa.

Some countries are tightening border controls due to the spread of the new variant. Here is the latest:

Japan will tighten border controls for the southern African nations of Mozambique, Malawi and Zambia, requiring a 10-day quarantine for any entrants, its Foreign Ministry said on Saturday.

Thailand on Saturday said it would ban entry of people traveling from eight African countries it designated as high-risk for the variant.

Starting in December, travel from Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, South Africa and Zimbabwe to Thailand will be prohibited.

Oman has suspended entry to travelers from South Africa, Namibia, Botswana, Zimbabwe, Mozambique, Lesotho and Eswatini starting from November 28, the country's state news agency tweeted on Saturday.

New Zealand will ban entry to travelers from nine southern African countries – South Africa, Namibia, Zimbabwe, Botswana, Lesotho, Eswatini, Seychelles, Malawi and Mozambique – from the start of next week.